Mobile platforms, such as planes, trains, buses, and ships, often must be quickly and easily reconfigured to accommodate changing seating requirements, and to accommodate varying combinations of passenger and cargo payloads. Typically, the task of seat reconfiguration is made difficult by the presence of a multitude of wires and cables running through the floor and seat tracks to provide audio and video entertainment, telephone services, reading light controls, connection to a LAN for Internet access, and electrical power to the passenger seats.
Not only does the multitude of wiring in the seat track make seat reconfiguration difficult, but also the weight of the many wires and cables reduces performance of the mobile platform, such as fuel economy, range, and payload. Additionally, the reliability of seat cabling is poor because the seat environment is hostile. Seat connectors and cables are often damaged or tampered with by passengers and the cabin floor environment can be dirty and wet. The cost of repair and maintenance on seat wiring is a significant expense.
Furthermore, PSUs that provide signal distribution and service switching are typically located under the passenger seats. Location of the PSUs under the passenger seats occupies valuable passenger legroom and storage space, and expose the PSUs to a harsh environment.
At least one wireless IR systems has been implemented to abate the problems with wired systems. Such a system works by flooding the cabin with diffuse and non-directional IR signals to be distributed to the passenger seats. With diffuse IR systems, received signal power is very limited because of scattering off of cabin walls, ceiling, seats, etc. The signal level can vary widely with propagation path changes caused by cabin reconfiguration, seats reclining, service cart movement, and passenger movement. Additionally, diffuse IR receivers gather light over large acceptance angles making them more sensitive to background light interference. Furthermore, diffuse wireless IR signal distribution does not support wide bandwidth video transmission because of low received signal amplitude. Further yet, to avoid interference, all passengers receive the same signal so they must share the very limited signal bandwidth.
Therefore, it is desirable to provide a LAN onboard a mobile platform that relocates the PSUs from below the passenger seats, eliminates wires and cables to the passenger seat, and avoids the problems associated with diffuse IR signal distribution by providing a direct path wireless IR link between the seat and the PSU.